Future extreme wildfires may be fueled by climate change

Climate change may favor larger and more destructive wildfires in the American West in the future, according to new research led by Michigan State University scientists.

Fires showing erratic behaviors are often harder to contain and result in catastrophic damage and loss of property and life.

“Our findings suggest that future lower atmospheric conditions may be conducive to larger and more extreme wildfires, posing an additional challenge to fire and forest management,” said Lifeng Luo, MSU assistant professor of geography and lead author on the study.

The study appears in the Journal of Applied Meteorology and Climatology.

The researchers analyzed current and future climate patterns projected by multiple regional climate models and the effect of those patterns on an operational fire-weather index that is used for assessing the atmospheric potential for extreme or erratic wildfires. The study focused on mountainous western United States including Arizona, Idaho, Nevada, New Mexico, Utah and Wyoming, and focused on the month of August, the most active month for wildfires in the region.

August 2012 saw 3.6 million acres burn in the region, the most of any August since 2000. However, there were only 6,948 fires in August 2012 – the second fewest in that 12-year timeframe – meaning the fires were much larger.

Large wildfires are mainly driven by natural factors including the availability of fuel (vegetation), precipitation, wind, the location of lightning strikes and anthropogenic factors. In particular, the researchers found that exceptionally dry and unstable conditions in the earth’s lower atmosphere may be more frequent in the future, thus contributing to more “erratic and extreme fire behavior.”

“Global climate change may have a significant impact on these factors, thus affecting potential wildfire activity in the western United States,” the study says.

Co-authors of the MSU-led study include Ying Tang and Shiyuan Zhong from MSU, and Xindi Bian and Warren Heilman from the USDA Forest Service.